Abstract: In the title compound, C9H10N4O4·H2O, the triazole ring is nearly planar. The 1,3-dioxane-4,6-dione ring exhibits a half-chair conformation. Two intramolecular N-H·O hydrogen bonds, with OH distances of 2.23 (2) and 1.99 (2) Å, and two intermolecular O-H·N hydrogen bonds, with NH distances of 1.92 (3) and 1.94 (4) Å, are observed.